must peck
Regular verb: peck - pecked- pecked

Affirmation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I must peck
you must peck
she must peck
we must peck
you must peck
they must peck 	I must be pecking
you must be pecking
she must be pecking
we must be pecking
you must be pecking
they must be pecking	I must have pecked
you must have pecked
she must have pecked
we must have pecked
you must have pecked
they must have pecked	I must have been pecking
you must have been pecking
she must have been pecking
we must have been pecking
you must have been pecking
they must have been pecking	

Negation 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
I mustn't peck
you mustn't peck
she mustn't peck
we mustn't peck
you mustn't peck
they mustn't peck 	I mustn't be pecking
you mustn't be pecking
she mustn't be pecking
we mustn't be pecking
you mustn't be pecking
they mustn't be pecking	I mustn't have pecked
you mustn't have pecked
she mustn't have pecked
we mustn't have pecked
you mustn't have pecked
they mustn't have pecked	I mustn't have been pecking
you mustn't have been pecking
she mustn't have been pecking
we mustn't have been pecking
you mustn't have been pecking
they mustn't have been pecking	

Interrogative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
must I peck?
must you peck?
must she peck?
must we peck?
must you peck?
must they peck? 	must I be pecking?
must you be pecking?
must she be pecking?
must we be pecking?
must you be pecking?
must they be pecking? 	must I have pecked?
must you have pecked?
must she have pecked?
must we have pecked?
must you have pecked?
must they have pecked? 	must I have been pecking?
must you have been pecking?
must she have been pecking?
must we have been pecking?
must you have been pecking?
must they have been pecking? 	

Interro-negative form 	
Simple form 	V-ing form 	Perfect 	V-ing perfect 	
mustn't I peck?
mustn't you peck?
mustn't she peck?
mustn't we peck?
mustn't you peck?
mustn't they peck? 	mustn't I be pecking?
mustn't you be pecking?
mustn't she be pecking?
mustn't we be pecking?
mustn't you be pecking?
mustn't they be pecking? 	mustn't I have pecked?
mustn't you have pecked?
mustn't she have pecked?
mustn't we have pecked?
mustn't you have pecked?
mustn't they have pecked? 	mustn't I have been pecking?
mustn't you have been pecking?
mustn't she have been pecking?
mustn't we have been pecking?
mustn't you have been pecking?
mustn't they have been pecking?